Human tumors often contain slowly proliferating cancer cells that resist treatment but we do not know precisely how these cells arise. We show that rapidly proliferating cancer cells can divide asymmetrically to produce slowly proliferating G0-like progeny that are enriched following chemotherapy in breast cancer patients. Asymmetric cancer cell division results from asymmetric suppression of AKT/PKB kinase signaling in one daughter cell during telophase of mitosis. Moreover, inhibition of AKT signaling with small molecule drugs can induce asymmetric cancer cell division and the production of slow proliferators. Cancer cells therefore appear to continuously flux between symmetric and asymmetric division depending on the precise state of their AKT signaling network. This model may have significant implications for understanding how tumors grow, evade treatment, and recur.
Asymmetric cancer cell division regulated by AKT.
Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
A post-transcriptional program of chemoresistance by AU-rich elements and TTP in quiescent leukemic cells.
Specimen part, Cell line, Treatment
View SamplesQuiescence (G0) is a transient, cell cycle-arrested state. By entering G0, cancer cells survive unfavorable conditions such as chemotherapy and cause relapse. While G0 cells have been studied at the transcriptome level, how post-transcriptional regulation contributes to their chemoresistance remains unknown. We induced chemoresistant and quiescent (G0) leukemic cells by serum-starvation or chemotherapy treatment. To study post-transcriptional regulation in G0 leukemic cells, we systematically analyzed their transcriptome, translatome, and proteome. We find that our resistant G0 cells recapitulate gene expression profiles of in vivo chemoresistant leukemic and G0 models. In G0 cells, canonical translation initiation is inhibited; yet we find that inflammatory genes are highly translated, indicating alternative post-transcriptional regulation. Importantly, AU-rich elements (AREs) are significantly enriched in the up-regulated G0 translatome and transcriptome. Mechanistically, we find the stress-responsive p38 MAPK-MK2 signaling pathway stabilizes ARE mRNAs by phosphorylation and inactivation of mRNA decay factor, tristetraprolin (TTP) in G0. This permits expression of ARE mRNAs that promote chemoresistance. Conversely, inhibition of TTP phosphorylation by p38 MAPK inhibitors and non-phosphorylatable TTP mutant decreases ARE-bearing TNFα and DUSP1 mRNAs and sensitizes leukemic cells to chemotherapy. Furthermore, co-inhibiting p38 MAPK and TNFα—prior to or along with chemotherapy—substantially reduced chemoresistance in primary leukemic cells ex vivo and in vivo. These studies uncover post-transcriptional regulation underlying chemoresistance in leukemia. Our data reveal the p38 MAPK-MK2-TTP axis as a key regulator of expression of ARE bearing mRNAs that promote chemoresistance. By disrupting this pathway, we developed an effective combination therapy against chemosurvival.
A post-transcriptional program of chemoresistance by AU-rich elements and TTP in quiescent leukemic cells.
Cell line, Treatment
View SamplesQuiescence (G0) is a transient, cell cycle-arrested state. By entering G0, cancer cells survive unfavorable conditions such as chemotherapy and cause relapse. While G0 cells have been studied at the transcriptome level, how post-transcriptional regulation contributes to their chemoresistance remains unknown. We induced chemoresistant and quiescent (G0) leukemic cells by serum-starvation or chemotherapy treatment. To study post-transcriptional regulation in G0 leukemic cells, we systematically analyzed their transcriptome, translatome, and proteome. We find that our resistant G0 cells recapitulate gene expression profiles of in vivo chemoresistant leukemic and G0 models. In G0 cells, canonical translation initiation is inhibited; yet we find that inflammatory genes are highly translated, indicating alternative post-transcriptional regulation. Importantly, AU-rich elements (AREs) are significantly enriched in the up-regulated G0 translatome and transcriptome. Mechanistically, we find the stress-responsive p38 MAPK-MK2 signaling pathway stabilizes ARE mRNAs by phosphorylation and inactivation of mRNA decay factor, tristetraprolin (TTP) in G0. This permits expression of ARE mRNAs that promote chemoresistance. Conversely, inhibition of TTP phosphorylation by p38 MAPK inhibitors and non-phosphorylatable TTP mutant decreases ARE-bearing TNFα and DUSP1 mRNAs and sensitizes leukemic cells to chemotherapy. Furthermore, co-inhibiting p38 MAPK and TNFα—prior to or along with chemotherapy—substantially reduced chemoresistance in primary leukemic cells ex vivo and in vivo. These studies uncover post-transcriptional regulation underlying chemoresistance in leukemia. Our data reveal the p38 MAPK-MK2-TTP axis as a key regulator of expression of ARE bearing mRNAs that promote chemoresistance. By disrupting this pathway, we developed an effective combination therapy against chemosurvival.
A post-transcriptional program of chemoresistance by AU-rich elements and TTP in quiescent leukemic cells.
Specimen part, Treatment
View SamplesVitiligo Blood Transcriptomics Provides New Insights into Disease Mechanisms and Identifies Potential Novel Therapeutic Targets Abstract Background: Significant gaps remain regarding the pathomechanisms underlying the autoimmune response in vitiligo (VL), where the loss of self-tolerance leads to the targeted killing of melanocytes. Specifically, there is incomplete information regarding alterations in the systemic environment that are relevant to the disease state. Methods: We undertook a genome-wide profiling approach to examine gene expression in the peripheral blood of VL patients and healthy controls in the context of our previously published VL-skin gene expression profile. We used several in silico bioinformatics-based analyses to provide new insights into disease mechanisms and suggest novel targets for future therapy. Results: Unsupervised clustering methods of the VL-blood dataset demonstrate a disease-state-specific set of co-expressed genes. Ontology enrichment analysis of 99 differentially expressed genes (DEGs) uncovers a down-regulated immune/inflammatory response, B-Cell antigen receptor (BCR) pathways, apoptosis and catabolic processes in VL-blood. There is evidence for both type I and II interferon (IFN) playing a role in VL pathogenesis. We used interactome analysis to identify several key blood associated transcriptional factors (TFs) from within (STAT1, STAT6 and NF-kB), as well as hidden (CREB1, MYC, IRF4, IRF1, and TP53) from the dataset that potentially affect disease pathogenesis. The TFs overlap with our reported lesional-skin transcriptional circuitry, underscoring their potential importance to the disease. We also identify a shared VL-blood and -skin transcriptional hot spot that maps to chromosome 6, and includes three VL-blood dysregulated genes (PSMB8, PSMB9 and TAP1) described as potential VL-associated genetic susceptibility loci. Finally, we provide bioinformatics-based support for prioritizing dysregulated genes in VL-blood or skin as potential therapeutic targets. Conclusions: We examined the VL-blood transcriptome in context with our (previously published) VL-skin transcriptional profile to address a major gap in knowledge regarding the systemic changes underlying skin-specific manifestation of vitiligo. Several transcriptional hot spots observed in both environments offer prioritized targets for identifying disease risk genes. Finally, within the transcriptional framework of VL, we identify five novel molecules (STAT1, PRKCD, PTPN6, MYC and FGFR2) that lend themselves to being targeted by drugs for future potential VL-therapy.
Vitiligo blood transcriptomics provides new insights into disease mechanisms and identifies potential novel therapeutic targets.
Specimen part, Disease, Disease stage
View SamplesColorectal cancer cells with TP53 mutation are highly resistant to chemotherapeutics. In order to identify potential chemo-resistance signatures, here; we explored the global gene expression profiles of drug resistant colorectal cancer cell line SW480 upon Floxuridine (FdUrd) treatment using Illumina Human HT-12 v4.0 Expression Beadchip Array. Further, significantly altered genes were subjected to the pathway analysis in GeneCodis3 and crucial signaling pathways were found to be enriched. Upon further functional validations, these pathways could be targeted to enhance therapy in human cancers harboring mutant p53.
Transcriptome profiling identifies genes and pathways deregulated upon floxuridine treatment in colorectal cancer cells harboring GOF mutant p53.
Sex, Age, Specimen part, Cell line, Treatment
View SamplesWe recently demonstrated that Msx genes, which encode muscle segment homeobox (Msh) transcription factors, regulate the transition of the luminal epithelium from high to low apicobasal polarity that is critical for implantation. In Msx deficient uteri (Msx1d/d/Msx2d/d), apicobasal polarity remains high and implantation fails to occur. However, information on the underlying molecular mechanism of Msx-dependent regulation of epithelial polarity, and the nature of epithelial-mesenchymal interactions that are characteristic of Msx genes, remain limited. In this study, we analyzed gene expression by RNA-sequencing in the luminal epithelium and stroma isolated by laser capture microdissection (LCM) on day 4 of pseudopregnancy in Msx1f/f/Msx2f/f and Msx1d/d/Msx2d/d uteri. We found upregulation of extracellular matrix components in the stroma and downregulation of immunity-related genes in both the luminal epithelium and stroma isolated from Msx1d/d/Msx2d/d mice. In addition, tight junction protein Claudin 1 and small proline-rich protein (Sprr2) were substantially upregulated in Msx1d/d/Msx2d/d epithelia. Overall design: mRNA profiles of luminal epithelium and stroma from a wildtype Msx1f/f/Msx2f/f and a uterine-specific knockout Msx1d/d/Msx2d/d mouse were asessed by RNA-sequencing with the Illumina HiSeq 1500 system
Uterine inactivation of muscle segment homeobox (Msx) genes alters epithelial cell junction proteins during embryo implantation.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
Targeting fibroblast growth factor receptors blocks PI3K/AKT signaling, induces apoptosis, and impairs mammary tumor outgrowth and metastasis.
Specimen part
View Samples4T1 mouse mammary carcinoma cells have an autocrine FGFR active loop leading to constitutive activation of downstream signaling pathways. We found that FGFR inhibitors have a strong effect on the proliferation and survival of these cells.
Targeting fibroblast growth factor receptors blocks PI3K/AKT signaling, induces apoptosis, and impairs mammary tumor outgrowth and metastasis.
Specimen part
View Samples4T1 mouse mammary carcinoma cells have an autocrine FGFR active loop leading to constitutive activation of downstream signaling pathways. We found that FGFR inhibitors have a strong effect on 4T1 tumors in-vivo.
Targeting fibroblast growth factor receptors blocks PI3K/AKT signaling, induces apoptosis, and impairs mammary tumor outgrowth and metastasis.
Specimen part
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